package com.fast.fastenjoy.components.sys.manager;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.util.Random;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Service;

/**
 * 随机验证码生成管理器器
 * @author chenliaohua
 *
 */
@Service("randomValidateCodeManager")
public class RandomValidateCodeManager {

	public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";// 放到session中的key
	private Random random = new Random();
	private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";// 随机产生的字符串

	private int width = 80;// 图片宽
	private int height = 26;// 图片高
	private int lineSize = 40;// 干扰线数量
	private int strSize = 4;// 随机产生字符数量
	
	private static final Font DEFAULT_FONT = new Font("Fixedsys", Font.CENTER_BASELINE, 18);

	/**
	 * 获得字体
	 * @return
	 */
	public Font getRandFont() {
		return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
	}

	/**
	 * 获取随机颜色
	 * @param fc
	 * @param bc
	 * @return
	 */
	private Color getRandColor(int fc, int bc) {
		
		if (fc > 255) fc = 255;
		if (bc > 255) bc = 255;
		
		int r = fc + random.nextInt(bc - fc - 16);
		int g = fc + random.nextInt(bc - fc - 14);
		int b = fc + random.nextInt(bc - fc - 18);
		
		return new Color(r, g, b);
	}

	/**
	 * 验证随机码是否正确的
	 * @param modelName
	 * @param value
	 * @param request
	 * @return
	 */
	public boolean verifyRandCode(String id, String value, HttpServletRequest request){
		
		String sessionKey = getSessionKey(id);
		
		String attribute = String.valueOf(request.getSession().getAttribute(sessionKey));
		
		return StringUtils.equalsIgnoreCase(attribute, value);
	}
	
	/**
	 * 生成并加载随机图片
	 * @param modelName
	 * @param request
	 * @param response
	 */
	public RenderedImage getRandcodeImg(String modelId, HttpServletRequest request, HttpServletResponse response) {
		
		return _getRandcodeImg(modelId, width, height, lineSize, strSize, request);
	}
	
	/**
	 * 生成并加载随机图片
	 * @param modelName
	 * @param request
	 * @param response
	 */
	private RenderedImage _getRandcodeImg(String modelId, int width, int height, int lineSize, int strSize, HttpServletRequest request) {
		
		HttpSession session = request.getSession();
		// BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
		Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
		g.setColor(getRandColor(110, 133));
		
		// 绘制干扰线
		for (int i = 0; i <= lineSize; i++) {
			drowLine(g);
		}
		
		// 绘制随机字符
		String randomString = "";
		for (int i = 1; i <= strSize; i++) {
			randomString = drowString(g, randomString, i);
		}
		
		String sessionKey = getSessionKey(modelId);
		
		session.removeAttribute(sessionKey);
		session.setAttribute(sessionKey, randomString);
		
		g.dispose();
		
		return image;
	}

	/**
	 * 绘制字符串
	 * @param g
	 * @param randomString
	 * @param i
	 * @return
	 */
	private String drowString(Graphics g, String randomString, int i) {
		g.setFont(DEFAULT_FONT);
		g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
				.nextInt(121)));
		String rand = String.valueOf(getRandomString(random.nextInt(randString
				.length())));
		randomString += rand;
		g.translate(random.nextInt(3), random.nextInt(3));
		g.drawString(rand, 13 * i, 16);
		return randomString;
	}

	/**
	 * 绘制干扰线
	 * @param g
	 */
	private void drowLine(Graphics g) {
		int x = random.nextInt(width);
		int y = random.nextInt(height);
		int xl = random.nextInt(13);
		int yl = random.nextInt(15);
		g.drawLine(x, y, x + xl, y + yl);
	}

	/**
	 * 获取session key
	 * @param modelName
	 * @return
	 */
	private String getSessionKey(String modelName){
		
		return new StringBuffer(modelName).append(RANDOMCODEKEY).toString();
	}
	
	/**
	 * 获取随机的字符
	 * @param num
	 * @return
	 */
	private String getRandomString(int num) {
		return String.valueOf(randString.charAt(num));
	}

}
